This invention relates to horizontal combination compressor and motors which are hermetically sealed within a case; and more particularly to such sealed compressors and motors installed in air conditioners, refrigerators, freezers, and the like. More specifically, the invention relates to a compressor and motor of the type in which the enclosing sealed case is divided by a partition plate into a compressor chamber and a motor chamber. By maintaining the surface level the lubricating oil in a compressor chamber oil sump higher than that of lubricating oil in the motor chamber, lubricating oil is stably supplied to the bearings of the compressor rotor shaft.
In general, a horizontal tape, hermetically-sealed, rotary compressor has a sealing case whose interior is divided by a partition plate into a compressor chamber in which a compressor device is accommodated and a motor chamber in which an electric motor for driving the compressor device is accommodated. In a compressor of this character, the rotor of the electric motor and the eccentric rotor of the compressor device are coupled by a horizontal rotor shaft, which is rotatably supported within the sealed case by bearings. It is necessary to supply lubricating oil to the rotationally sliding parts between the rotor shaft and its bearings. For this purpose, it has been a conventional practice to forcibly supply lubricating oil to the parts requiring lubrication by pumping lubricating oil up from an oil sump at the bottom of the sealed case by means of an oil supply pump.
For obtaining a stable positive supply of lubricating oil, it is advantageous to set the oil surface in the oil sump in the compressor chamber at a higher level than that in the motor chamber. For this purpose, it has been the practice heretofore to conduct the gaseous refrigerant which has been compressed by the compressor device through an external connection pipe installed outside of the sealed case to the motor chamber, and to hold down the height of the oil surface in the oil sump within the motor chamber while maintaining the oil surface on the compressor chamber side at a high level. In this connection, the gaseous refrigerant at high pressure which has been thus conducted to the motor chamber is returned again to the compressor chamber through a gap between the stator and rotor of the electric motor or through vent passages formed in the stator and is then sent through a delivery pipe to a condenser of the refrigeration system (as described in Japanese Utility Model Application "Kokai" Publication No. 10992/1986).
The above described conventional compressor, however, tends to become bulky in size and requires a large installation space because of the installation of the connection pipe outside of the sealed case. Furthermore, the connection pipe is easily damaged during transportion or at the time of installation.